block: respect error code from bdrv_getlength in handle_aiocb_write_zeroes

Original idea beyond the code in question was the following: we have failed
to write zeroes with fallocate(FALLOC_FL_ZERO_RANGE) as the simplest
approach and via fallocate(FALLOC_FL_PUNCH_HOLE)/fallocate(0). We have the
only chance now: if the request comes beyond end of the file. Thus we
should calculate file length and respect the error code from that op.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Markus Armbruster <armbru@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Denis V. Lunev 2017-08-04 18:10:11 +03:00 committed by Kevin Wolf
parent 0e51b9b7c7
commit 70d9110b44

View File

@ -1339,6 +1339,9 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
#if defined(CONFIG_FALLOCATE) || defined(CONFIG_XFS)
BDRVRawState *s = aiocb->bs->opaque;
#endif
#ifdef CONFIG_FALLOCATE
int64_t len;
#endif
if (aiocb->aio_type & QEMU_AIO_BLKDEV) {
return handle_aiocb_write_zeroes_block(aiocb);
@ -1381,7 +1384,10 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
#endif
#ifdef CONFIG_FALLOCATE
if (s->has_fallocate && aiocb->aio_offset >= bdrv_getlength(aiocb->bs)) {
/* Last resort: we are trying to extend the file with zeroed data. This
* can be done via fallocate(fd, 0) */
len = bdrv_getlength(aiocb->bs);
if (s->has_fallocate && len >= 0 && aiocb->aio_offset >= len) {
int ret = do_fallocate(s->fd, 0, aiocb->aio_offset, aiocb->aio_nbytes);
if (ret == 0 || ret != -ENOTSUP) {
return ret;